Process and apparatus for making sheet glass



PROCESS AND AFPHATUS FOR MAK-ING SHEET GLASS Eiled Dec. l2, 3.922 a Simms-Sheet l D@ mi; w24.

H. K. HTCHCOCK PROCESS AND APPARATUS FOR MAKING SHEET GLASS Filed Dec. 1g, v1922 www@ 4 Sheets-Sheet 2 Illlilill ill EN ill ill IIHHIUWH EN lll Ell Ell iH IH Ill Dec, 36, Q. 3,539,259

H, K. HTCHQQC/' PROCESS AND APPARATUS FOR MAKING SHEET GLASS Filed Dec. l, 1922 4 Sheets-Shet 3 @w i6; w24 Y www@ l H. K. HT'HCO-CK PROCESS AND APPARATUS ER MAKING SHEET GLASS Filed Dec. 12, 1922 4 Sheets-Sheet 4 VvE/ym@ JA fc. M25/M .Patented Dec. 16, 1924.

UNITED sra'ras estarse Parser orales?.

HALBEBT K. HITCHCOCK, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR F ONE-HALF lTO HITCHCOCK EXIEBIMENT COMPANY, A CORPORATION OF NEW JERSEY.

PWS AND APPABATUS'FOR MAKING SHEET GLASS.

Application tiled December l2, 1922. Serial No. 806,388.

To all lwlwm it may concern:

Be it known that I, HALBERT K. Hironoox, a citizen of the United States, and a resident of Pittsburgh, in the county ot 6 Allegheny and State of Pennsylvania, have made a newand useful invention in Improvements in Processes and Apparatus for Making Sheet Glass, of which the following is a specification. 10 The invention relates to the continuous formation of sheet glass by withdrawing it vertically from a tank or receptacle, and constitutes an improvement over 'what is shown in my Patent No. 805,064 of Nov. 2l, l5 1905. It also involves a modification o the structure shown in my application No. 569,000, filed June 17, 1922, such ap lisation disclosing the formation .of the sieet upwardly instead of downwardly, but involv- 29 ing the use of rolls at the outlet similar in construction and function to those ot said a plication. The present invention involves -t e employment of gravity to secure the necessary feeding and stretching action upon the glass sheet, as opposed to the mechanical means for drawing the sheet upwardly as disclosed in said application, and provi es for turning the sheet laterally and feeding' it through a horizontal leer instead 30 of carrying it through u v'ertical leer. The invention has for its principal objects the provision of an improved construction of the type specified wherein a tint sheet is secured with both surfaces .tree from warring and requiring no grinding or polishing, and the provision of'a construction in which the gravity feed maybe regulated to give the. desired thickness of glass and speed ot dra One embodiment of the invention is illus- 40 trated in the accouxpanying drawings.

wherein:

Flgure 7. 1s a partial vertical section through the assembled apparatus;- Fig. 2 is an irregular transverse section on the line H-H of F ig. 1; Fig. 3 is an enlarged vertical section through a portion of the construction shown in Fig. 1; Figs. 4 and 5 are detail views showing the means for mountingr the rolls for radial adjustment; and Fig. 6 1s an enlarged detail section' showing the method of mounting the guide rolls and driving them.

Referring to the drawings, l is the iorward end of the melting tank provided with b forehearth 2 and the gate 3 by means of whichcommunication may be cut oil' from the tank to the forehearth. The tank and forehearth are provided with suitable means for heating and a` transverse flue 4 is pro- .vided immediately beneath the gate so that additional heat may be supplied at this point after the gate has been closed and the operationis to be again started up. The bottom or iioor 5 of the forehearth is rovided with an outlet slot 6 through-wine the glass is withdrawn which is to form the sheet.- i

immediately below the slot 6 is the rolling or sizing apparatus which is preferably mounted upon a transversely movable car 7 carried by the rails 8 so that this portion ot the apparatus may be readily moved out of position, when desired, for repair purposes or to give better access to the portions of the construction lying above and below the car. Mounted upony the car are a pair oi opposing air cooled rolls 9 and 10, vpreferably of nichrome or Mone] metal or some other heat resisting composition whose sur- 'face will not deteriorate after continued contact with the molten glass and such surface is highly polished to reduce any marring effect upon the glass to a minimum. Y The details of construction ot these rolls and the method oi' cooling them constitute no part ci my present invention, suclrconstruction being fully set forth in my pending appli-- cation heretofore referred to, and it will be understood that various means might-bc employed for "securing a uniform cooling action upon these rolls. Devices for-chilling the glass below the rolls are provided in the torm of the water cooled members 9iL extending transversely ci' the glass sheet.

rolls are preferably driven forwardly at a rate corresponding to the movement of the glass through the slot, but if desired, they may be driven at a different rate of speed or may be driven in a reverse direction. The purpose is to size or form the sheet ot glass to a uniform thickness throughout and to impart a certain amount ot cooling effect to the sheet. Such cooling action will not be sulicient, however, to impart a permanent set to the surtaceiof the glass, the volume of glass passing between the rolls being such and the temperature of the glass being such that after the sheet has passed the rolls, the heat in the body -of glass itsehc will cause a tire tinish effect upon the surface et the sheet and prevent any impressions received upon the surfaces of the glass from the rolls from becoming permanen.

Tie rolls are pivotally supported at each end of said casing 11 by meansof the levers 19. and 13 pivoted at 14 and 15 and engaged at their lower ends by the links 1G and 1T. These links are pivotcd at their lower ends to a sliding block 18 and this block is moved up and down by the rod 19 which has right and left hand threads at its t-wo ends, the upper of which is threaded into the casing and the lower into the block. The swinging.'

of the levers in and out gives an adjustment of 'the rolls 9 and 10. In order to adjust the rolls vertically, the casing'll is provided at its four corners with lugs 20 carrying the set screws 21 bearing at their lowerends upon the angle irons Q2 forming a part of the framework of the car or truck 7.

The rolls f) and 1t" are preferably driven from an electric motor 225 carried by the cas` ing 11 and provided with a driving sprocket. 24. A suitable sprocket chain 25 passes around this sprocket 24, around suitable sprockets on the ehds of the rolls 9 and 10 as indicated in Fig. 3 and over the. idler sprocket 26.

Immediately below the car is the chamber QT'through which the glass sheet or ribbon 28 is conducted to the entrance end of the roller leer 29. In order to ruide the sheet 4during its movement througi this` chau'lbcr and also to provide an adjustable. support for the sheet as hereinafter set forth, the series of guide rolls 30 are employed, such rolls extending at their ends through the side walls 31 of the chamber 27 as indicated in Fig. 4suitable packingr 32beiing vprovided around the ends of the rolls to prevent drafts into the chamber. Alternate rolls are. preferably provided with flanges 33 which serve :is guides for the edges of the sheet 33 to prevent it 'from working ont of its proper posit-ion on the rolls. A rigid metal framework 34 is mounted along the side walls 3lof the chamber 27, such framework serving to carry the hearings 35 in which the rolls 230 are. mounted. These bearings are mounted for adjustment. trz'nsversely with respect to the sheet 28 by mean-s` of the. arms 36 formed integral with the bearings. These arms are mounted in grooves 37 in the framework as indicated in Fig. G and are clamped in Iposition by means of the bolts 38 extending through the slots 39 in the arms. In this manner each roll may be, adjusted in and out for the purpose more fully hereinafter set forth. Each rollis provided at one. of its ends with a sprocket 40 and these sprockets are all driven from the chain 41. A transverse shaft 42 extends parallel to and adjacent the lowest roll 30 and carries at its end the sprocket around which the 'chain is looped and then passed back to the drive motor 425. '.lhis motor has upon its drive 'shaft a sprocket 44 which acts as the driving element of the chain 4l. The chain at. its upper end is looped around a sprocket carried by the end of the transverse. shaft 45 and then passes around the adjustable idler sprocket 46 and the motor sprocket 44.

Immediately below the car 7 is a pair of guide rolls 47 and 48 which are driven at thel sai`ne`rate of speed as the rollers 30. These rolls are spaced apart a distance slightly greater than the thickness of the sheet so that when the sheet ismaintained in vertical position by its weight substantially no pressure will be exerted upon the sheet at any time tending to mar it. but at the lsame time. any substantial shifting of the plate from a vertical position is prevented. These rolls are driven by a sprocket chain 4t) which passes around a sprocket 30 (Fig. (i) on the uppermost one of the set of-gnide rolls 30. over the. top of' a sprocket on the end of the roll 48, across the lower side of a sprocketon the end of the roll 47 and around an idler roll 50.

The speed of draw is preferably regulated by the amount of p ull imposed upon the sheet by gravity. The sheet in Fig. 1 is shown as first engaging the roll 30, so that the. sheet is entirely unsupported until it reaches this' roll. lfv it. is desired to increase the weight upon the sheet in order to increase the speed of draw` the roll 30* is adjusted tothe rear so that the sheet first engages the roll next. below the roll 30X. On the. other hand, if it is desired to' decrease the. pulling force or gravity upon the sheet and so decrease the speed of draw and thicktn the sheet, the roll just above. the roll 3ft* is adjusted outward until it touches the sheet. If the change in adjustment extends any considerable. distance along the set of rolls. it becomes desirable to adjust several of the rolls below'the point where the sheet. first engages a roll so as to modify the cnrvature of the guideway. In this way any desired pull upon the sheet may be secured. lt will be understood,however, that many alternative expedients might be employed to secure this varying point of engagement with the curved guideway, and that the invention is not limited to the use of a roller guideway, although this is the preferred form and reduces thetendency of the sheet to. be marredulpon engagement with theI guideway to a minimum.

T he cooling of'the sheet after passing the. I

rolls 9 and 1f) is so regulated that when the sheet engages the. first guide roll 30, its surface has hardened sufficiently to avoid mai-ring although there is sufficient. flexibility in the' sheet to permit it to follow the curved gnideway below this point. The contactof the. sheet upon the first few guide Apasses into the leer heating coils 51 embedded in the face of the wall 52. The heating coils are divided into sections so that the heat may be distributed in the chamber in any desired Way. The chamber is also provided with openings 53 and` gas burners 54 for supplying any additional heat required.

From the roller guideway, the sheet 29 which is illustrated as having a carrier for the glass consisting of a set of rolls 55 spaced at suitable distances and rotated so as to convey the sheet through the leer as it is formed. The sheet which has a slight curvature as it enters the leer is tiattened as it progresses into the leer,

the sheet having sufficient flexibility to permit of this flattening operation. The rolls are driven by a sprocket chain 56 which passes along sprockets on the outer ends of the rolls and around a driving sprocket on the shaft 57. The shaft 57 also carries a spur gear 58 meshing with a spur gear 59 on the shaft 42. The lower flight of the chain 56 passes around the idler take-up roller 60. Y

What I claim is:

1. In apparatus for forming sheet glass. a glass container adapted to carry a bath of glass therein provided with refractory bottom With an outlet slot therethrough, a pair of rolls adjacent said slot. means for cooling the rolls. a cu'rved guideway below the rolls for receiving the sheet formed between the rolls and carrying it laterally, and ineans whereby' the guideway may be adjusted so as to engage-the sheet at varying distances below the rolls and so regulate the tension imposed by gravity upon the sheet.

2. In apparatus for forming sheet glass. a glass container adapted to carry a bath ofglass therein provided with a refractory 'bottom with an outlet slot theretlirough` a pair of rolls adjacent lsaid slot, means for cooling the rolls, means foil driving the rolls, a curved ruideway below the rollsl for receiving the slieet.- formed between the rolls and carrying it laterally. and means whereby the guideway may be adjusted so as to engage the sheet at varying distances below the rolls and so regulate the tension imposed by gravity upon the sheet.

8. In apparatus for forming sheet glass` a glass container adapted to carry a bath of glass therein provided with a refractory boittom with an outlet slot therethrmigh` a pan' of rolls adjacent said slot, means for cooling guideway being positioned such a distance below the rolls that the, surface of the sheet may harden beyond the marring point be tore it reaches said guideway.

4. In apparatus for forming sheet glass, a glass container adapted to carry a bath of glass therein provided with a refractory bottom with an outlet slot therethrough, a pair of rolls adjacent Said slot, means for cooling the roll a curved .guideway below the rolls for receiving the sheet formed between the rolls and carrying it laterally. such guideway being provided with a series of rollers and means for adjusting the rollers to change the curvature of the. guideway and the distance below said rolls at which the' sheet first engages one of said rollers.

5. The process of forn'iing a continuous glass sheet or ribbon which consists in flow-4 ing it vertically from a bath of molten glass` passing the sheet through a cooling aperture to reduce it to a uniform thickness, permit.- ting the glass to stretch of its own weight and-engaging the sheet after it has hardened bevond thelmarr'ing point and guidi/ng it. laterally into a leer.

6. The process of forming a continuous glass sheet or ribbon which 'consists in flowing it'v'ertically from a bath of molten glass, passing the sheet through a cooling aperture to reduce it to a uniform thickness at a temperature such that it will fire nish from its own heat after such reduction to uniform thickness, permitting the surface. of the glass to harden, and then engaging the sheet and guiding it laterally through a leer.

7. The process of forming a continuons glass sheet or ribbon which consists in flowing it vertically from a bath of molten glass. passing the sheet through a cooling aperture and rolling or sizing it to reduce it to a uniform thickness. permitting the glass to stretch of its own weight. after said rolling or .sizing and its surface to harden and linally engaging it and `turning it laterally into a leer.

8. 'lhe process ot' forming a continuous glass sheet or ribbon which consists in {lowing it. vertically from a bath of molten glass. rolling or forming the sheet into a relatively thick sheet'. of substantially uniform (hickness from edge. to edge. chilling the surface ofthe glass adjacent the rolls/permitting the glass' to stretch of itsI own weight. and inally engaging the sheet and turning it laterally into a leer. j

In testimony whereof` subscribed my naine this lith day 1922.

l have hereunto of Nov.. 

